Abstract: Photoinduced deformation of liquid crystal polymer materials has attracted extensive attention in recent years because it can realize the direct conversion from light energy to mechanical energy. According to the development trend and practical application requirements of light-induced deformation liquid crystal polymer materials, a new structure of visible and near-infrared light-induced deformation liquid crystal polymer materials is discussed and developed in this paper. Firstly, a novel visible light responsive linear liquid crystal polymer containing reactive groups was prepared by multi-step organic synthesis reaction, and then a large-size visible light deformable liquid crystal polymer material was prepared by post-crosslinking strategy. In addition, the up-conversion luminescence of rare earth nanoparticles is used for the first time to realize the near infrared deformation of liquid crystal polymer materials. The main results are as follows: 1) Preparation and properties of a novel visible light responsive linear liquid crystal polymer containing reactive groups. Visible light responsive liquid crystal monomer 2- methyl-4- (4 "-succinimidylphenylalkynyl) -4'-[ 1 1- (acryloxy) undecalkoxy] azobenzene (M 1) and non-photoresponsive liquid crystal monomer 4-hexyl were prepared by multi-step organic synthesis reaction. Then, by free radical polymerization, the post-crosslinking linear polymer PM 1 was prepared from the monomer M 1, and the random polymer PM 1 m2 with low photoresponsive group content was prepared from the monomers M1and m2 * * poly. The structures of monomers and polymers were characterized by 65438+ 1H NMR, IR and gel permeation chromatography. The results of DSC and POM analysis show that the monomers M 1 and M2, and the polymers PM 1 and PM 1M2 all have liquid crystal properties. At the same time, it was found that the glass transition temperature of PM 1M2 was significantly lower than that of PM 1 about 50℃, which was due to the inclusion of * * polymer component M2 in PM 1M2. In addition, the photoisomerization behaviors of polymers PM 1 and PM 1M2 under different wavelengths of visible light (405nm or 445nm) were discussed. It was found that both wavelengths of visible light could induce photoisomerization of photoresponsive groups, which was induced by visible light of cross-linked liquid crystal polymers (CLCP) composed of PM 1 and PM 1M2. 2) Preparation of large-size visible light-induced deformation liquid crystal polymer materials and discussion on its photo-induced deformation behavior. Using linear liquid crystal polymers PM 1 and PM 1M2 containing reactive groups, large-size CLCP films were prepared by spin coating technology, surface coating technology and post-crosslinking reaction. The photo-induced bending deformation behavior of CLCP thin film materials irradiated by visible light with different wavelengths (405nm and 445nm) is discussed. Both PM 1 thin films and PM 1M2 thin films can undergo rapid bending deformation under the irradiation of visible light with the wavelength of 405nm or 445nm. This is because the azodiphenylacetylene unit on the film surface undergoes cis-trans isomerization after absorbing light energy, and the arrangement of liquid crystal cells changes, which leads to the surface shrinkage of the film and causes bending deformation. After being irradiated or heated by visible light with a wavelength of 577nm, the bent film can be restored to its original flat state, and this process can be repeated many times.

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